[PATCH next v11 08/11] usb: roles: get usb-role-switch from parent

From: Chunfeng Yun
Date: Thu Aug 29 2019 - 05:23:24 EST


when the USB host controller is the parent of the connector,
usually type-B, sometimes don't need the graph, so we should
check whether it's parent registers usb-role-switch or not
firstly, and get it if exists.

Suggested-by: Heikki Krogerus <heikki.krogerus@xxxxxxxxxxxxxxx>
Signed-off-by: Chunfeng Yun <chunfeng.yun@xxxxxxxxxxxx>
---
v10~v11: no changes

v9:
1. replace signed-off-by by suggested-by Heikki
2. use class_find_device_by_fwnode()

v8: no changes
v7:
add signed-off-by Chunfeng

v6:
new patch
---
drivers/usb/roles/class.c | 25 +++++++++++++++++++++----
1 file changed, 21 insertions(+), 4 deletions(-)

diff --git a/drivers/usb/roles/class.c b/drivers/usb/roles/class.c
index 2abb6fe384ca..94b4e7db2b94 100644
--- a/drivers/usb/roles/class.c
+++ b/drivers/usb/roles/class.c
@@ -102,6 +102,19 @@ static void *usb_role_switch_match(struct device_connection *con, int ep,
return dev ? to_role_switch(dev) : ERR_PTR(-EPROBE_DEFER);
}

+static struct usb_role_switch *
+usb_role_switch_is_parent(struct fwnode_handle *fwnode)
+{
+ struct fwnode_handle *parent = fwnode_get_parent(fwnode);
+ struct device *dev;
+
+ if (!parent || !fwnode_property_present(parent, "usb-role-switch"))
+ return NULL;
+
+ dev = class_find_device_by_fwnode(role_class, parent);
+ return dev ? to_role_switch(dev) : ERR_PTR(-EPROBE_DEFER);
+}
+
/**
* usb_role_switch_get - Find USB role switch linked with the caller
* @dev: The caller device
@@ -113,8 +126,10 @@ struct usb_role_switch *usb_role_switch_get(struct device *dev)
{
struct usb_role_switch *sw;

- sw = device_connection_find_match(dev, "usb-role-switch", NULL,
- usb_role_switch_match);
+ sw = usb_role_switch_is_parent(dev_fwnode(dev));
+ if (!sw)
+ sw = device_connection_find_match(dev, "usb-role-switch", NULL,
+ usb_role_switch_match);

if (!IS_ERR_OR_NULL(sw))
WARN_ON(!try_module_get(sw->dev.parent->driver->owner));
@@ -134,8 +149,10 @@ struct usb_role_switch *fwnode_usb_role_switch_get(struct fwnode_handle *fwnode)
{
struct usb_role_switch *sw;

- sw = fwnode_connection_find_match(fwnode, "usb-role-switch", NULL,
- usb_role_switch_match);
+ sw = usb_role_switch_is_parent(fwnode);
+ if (!sw)
+ sw = fwnode_connection_find_match(fwnode, "usb-role-switch",
+ NULL, usb_role_switch_match);
if (!IS_ERR_OR_NULL(sw))
WARN_ON(!try_module_get(sw->dev.parent->driver->owner));

--
2.23.0